Backpack



FIG. 1 is a view of a backpack being work from the rear side of a wearer of my new design thereof;

FIG. 2 is a view of the backpack being work from the front side of a wearer thereof;

FIG. 3 is a view of the backpack being work from the side of a wearer thereof;

FIG. 4 is a front view of the backpack thereof;

FIG. 5 is a back view of the backpack thereof; and,

FIG. 6 is a front view of the backpack with a water bottle and a wallet inserted into the pockets thereof.

The broken lines showing a human form, a water bottle, and a wallet are for environmental purposes only and form no part of the claimed design. The broken lines in FIG. 5 depict stitching and form no part of the claim. 

CLAIM The ornamental design for a backpack, as shown and described. 